Alloy for dental use

ABSTRACT

AN ALLOY FOR USE IN DENTISTRY COMPRISING NICKEL, CHROMIUM, MOLYBDENUM, ALUMINUM, BERYLLIUM AND CARBON; WHICH ALLOY POSSESSES PHYSICAL PROPERTIES ADAPTING THE SAME FOR EFFECTIVE REPLACEMENT OF THE HERETOFORE UTILIZED GOLD AND GOLD ALLOYS. SAID ALLOYS IS OF MARKED STRENGTH WHILE BEING RELATIVELY LIGHTWEIGHT SO AS TO PROVIDE RELATIVELY THIN RESTORATION DEVICES WHILE ASSURING OF A PRECISE AND ACCURATE FIT.

3,749,570 ALLOY FOR DENTAL USE Richard L. Lyon, 6 Monterey Place, Alton,Ill. 62002 No Drawing. Filed May 26, 1971, Ser. No. 147,161

Int. Cl. C22c 19/00 US. Cl. 75-171 3 Claims ABSTRACT OF THE DISCLOSUREAn alloy for use in dentistry comprising nickel, chromium, molybdenum,aluminum, beryllium and carbon; which alloy possesses physicalproperties adapting the same for effective replacement of the heretoforeutilized gold and gold alloys. Said alloy is of marked strength whilebeing relatively lightweight so as to provide relatively thinrestoration devices While assuring of a precise and accurate fit.

BACKGROUND AND SUMMARY OF THE INVENTION This invention relates ingeneral to metal alloys and, more particularly, to a uniquelyconstituted alloy adapted for dental usage.

It is an object of the present invention to provide an alloy comprisedof so-called nonprecious metals, the usage of which will obviate theutilization of gold and alloys thereof for crown and bridge Work, aswell as related dental purposes.

It is a further object of the present invention to provide an alloy ofnonprecious metals for makingdental restorations, such as completecrowns, which is peculiarly adapted for reliably receiving porcelainveneers, as through baking.

It is a still further object of the present invention to provide a metalalloy of the type stated which, by obviating the heretofore acceptedresort to use of gold and alloys thereof, conduces to a substantialeconomy which has long been awaited in the dental field.

It is another object of the present invention to provide an alloy of thecharacter stated having physical properties equal or exceeding thecorresponding properties of casting gold in all of its conditions ofrelative hardness so that the use of the present alloy causes nodiminution to the individual in those advantages which had beenheretofore assumed peculiar to gold.

It is another object of the present invention to provide an alloy of thetype stated which is readily worked by the dentist so as to permitutilization of well known techniques.

It is another object of the present invention to provide an alloy ofnonprecious metals which may be produced by an inexpensively performedmethod; the use of which is reliable and durable and conduces to preciseand accurate fits.

DESCRIPTION OF THE PREFERRED EMBODIMENT In essence, this inventioncomprises a multi-metal alloy in which the major component is nickel andwhich embodies relatively lesser amounts of chromium, molybdenum,aluminum, and beryllium, together with a rela tively small amount ofcarbon. It has been found that the United States Patent 3,749,570Patented July 31, 1973 incorporation of these specific elements withinthe alloy is critical, although certain variations in relativeproportions, as by weight, is permitted without appreciable diminutionin the resultant properties.

The broad composition of this present alloy is as follows:

However, an alloy prepared in accordance with the pres ent invention andhaving the following specific composition has been extensively testedand proved of marked efiicacyt Percentage by weight, approx.

Carbon .l Beryllium 1.5 Aluminum 3 .0 Molybdenum 2.0 Chromium 12.0Nickel 8 1 .4

Alloys prepared in accordance with the foregoing have been demonstratedto have the following physical properties:

Density 7.8.

Brinell hardness 276.

Proportional limit 55,000 lbs. per sq. inch. Tensile strength 110,000 to115,000. Elongation 2%.

A study of the comparable properties of gold and the various gold alloysheretofore used in dentistry, including all of the grades of relativehardness of such gold, reveals that the alloy of this invention providesproperties of greater value than gold.

In actual practice, the present alloy as used for making dentalrestorations, such as so-called complete crowns, as well as standarddental castings, such as inlays and onlays, and bridges, has producedmyriad, unexpected advantages, including providing the construction ofstronger, more rigid and long span bridges; allowing for relativelythinner construction of crowns; being actually less bulky and, hence,relatively more sanitary by permitting more anatomical interproximalspace between abutments and pontics; and provides a more accurate andprecise fit. In addition for dental prothesis, the present alloyprovides a more permanent, non-tarnishing luster, while being ofrelative lightweight. Furthermore, it has been discovered that therelative hardness of crowns and the like formed of this alloy obviatesthe heretofore professional besetting problem of loss of centric due towear. Actually, the wear by attrition factor of this alloy isapproximately equal to that of the average natural tooth.

Another unexpected aspect from the use of the present invention indentistry is that the same provides sufiicient amount of burnishing andspinning without breaking or flaking for tight margins. The relativehigh tensile strength of the alloy maintains the requisite cohesivenessof the ingredients so that the metal alloy can be moved and subsequentlypolished without flaking or breaking.

In addition to the above described properties, this alloy maybeeffectively worked by the dentist utilizing presently known techniquesand allows of the reliable application of porcelain f-acings or veneers.Heretofore, on only certain types of gold alloys has it been possible tobake porcelain. Of extreme importance is the fact that this alloy may begold plated for enhancing the appearance of the porcelain veneer andacrylic veneers may be used in the customary manner.

In view of the foregoing it is thus apparent that restorationsconstructed of the present alloy can be relatively thinner than thosemade of gold and gold alloy, but with no diminution in strength,Accordingly, less time may be spent in preparation and with diminisheddestruction of tooth structure. Of especial importance it is theeconomic factor since the cost of this alloy is but a minor fraction ofthat for gold or gold alloy as currently used in dentistry.

The alloy may be prepared by melting the nickel and then adding thealloy ingredients therein with appropriate intermixture. While in amolten state the alloy may then be poured into molds for suitable ingotformation.

The generally known nickel-chromium alloys are of an 80:20 ratio.However, an alloy of this limited character does not possess the unusualproperties of the present alloy which renders it so adaptable for use indentistry. The incorporation of the four remaining elements endows thealloy of this invention with a capability of having applied thereonporcelain in a reliably bonded manner, which capacity is notdemonstratedby any other non-precious alloy heretofore known. The unique compositionof this alloy renders it useful in the casting of removable partialdenture frames to which gold clasp wires can be soldered. Furthermore,with the alloy of this invention, individual restorative units andrepairs can be accomplished by practising all currently known dentalsoldering techniques heretofore used with gold and silver. This uniquecapability is peculiar only to the alloy of this invention.

Carbon .03.3 Beryllium .3-3 .5 Aluminum .55 Molydenum .4-4 Chromium 8-20Nickel Balance 2. An alloy for dental prothesis consisting essentiallyPercentage by weight, approx Carbon ,1 Beryllium 1.5 Aluminum 3.0

Molydenum 2.0 Chromium 12.0

Nickel 81.4

3. An alloy for dental prothesis as defined in claim 1 and furthercharacterized by said alloy having a tensile strength of 110,000 to115,000; a proportional-limit of 55,000 p.s.i., a Brinell hardness of276, a density of 7.8, and an elongation of 2%.

References Cited UNITED STATES PATENTS 1,945,679 2/1934 Corson -1712,150,255 3/1939 Touceda 75-171 2,343,039 2/1944 Allen 75-171 2,575,91511/1951 Guy 75-171 3,005,704 10/1961 Faulkner 75-171 3,287,110 11/1966Scherbner 75-171 3,390,023 6/1958 Schira 75-171 HYLAND BIZOT, PrimaryExaminer

